Prior art brushrolls generally include a central spindle supported at either end by bearings mounted on the sides of the nozzle. The spindles are turned by belts tied to a vacuum cleaner motor, either directly or through one or more pulleys. Mounted on the elongated surface of the spindle is a plurality of tufts of bristles or beater bar elements projecting normally from the surface of the spindle. As the brushroll rotates, the tufts or beater bar elements brush against the surface of the carpet and loosen dirt from the fibres. The tufts or beater bar elements are generally mounted in a helical pattern on the brushroll so as to agitate the carpet seriatim as the vacuum cleaner moves over the carpet surface.
In practice, dirt and threads loosened by the brushroll can flow along the surface of the roll toward its ends into the bearings at the sides. As a result, the bearings can foul so that the brushroll cannot turn freely in response to the belt drive.
A number of thread guards have been proposed for preventing threads from fouling the brushroll bearings. These proposed thread guards include labyrinth seals which fit over the ends of the spindle in an effort to prevent threads moving outwardly along the spindle from reaching the bearing. One drawback to these thread guards is that they tend to be complicated and expensive to manufacture. Many do not lend themselves to modern manufacturing methods such as injection molding from plastic. There remains a need in the art for a brushroll which is simple and relatively inexpensive to fabricate and assemble.